Q: I know you've written a lot about automatic backup generators lately. But can I ask for one more comment on the issue? It would be extremely useful to have a detailed comparison of backup generators to solar panels and battery installations in homes. It is hard to find independent analyses such as you could provide.

A: You aren't the only person who has made this request. While I am very familiar with automatic backup generators and portable generators for home use because I've been using them for over a decade, I have not owned or reviewed solar equipment or battery installations. The best I can do is provide an overview of the leading systems and the costs, then direct you to a resource where you can finish the comparison on your own.

The best-known home solar panel and battery combination is the Tesla Powerwall. It uses solar panels to charge large batteries that store energy that can be used in your home every day, as well as for home emergency backup power. Your home's size and power requirements and the number of panels and batteries you have determines how long you can go without grid power.

A Powerwall will cost five times as much — or more — as an automatic backup generator, but you have to figure in that you will shave your monthly electric bill by using the power every day. If you want to save on your electric bill, help the planet by using clean solar energy and have backup power, the Powerwall could be a great option. But if your goal is just to have backup power in an emergency, the generator makes more sense.

You can learn more about the Powerwall system and get an estimate on the cost of a suitable system at tesla.com/powerwall.

Playing all the angles

Q: I'm getting into vinyl records, and I got caught in the middle of an argument about something I don't even understand. One friend said that it was crucial that I get a turntable with an adjustable vertical tracking angle, but another told me not to worry about it. What is it, and how important is it?

A: The vertical tracking angle (VTA) is the angle at which the stylus rests in the record groove. Some tonearms have adjustable VTA, while others require shims between the plinth (the body of the turntable) and the tonearm to adjust VTA. As you have discovered, how important it is depends on whom you ask. Some audiophiles consider adjusting the VTA to be vital to getting the best sound, but others think it's immaterial because the thickness of the records can vary, which throws off the VTA.

Send questions to Don Lindich at donlindich@gmail.com. Get recommendations and read past columns at soundadvicenews.com.